a friend of mine had a web site that they were about to demo to a potential client, and it had some CMS sort of capabilities, and they had filled it with lorem-ipsum type content, and "fake" urls: they just typed in a bunch of Xs. for example "xxxxx.xxx" ... of course, .xxx is a real TLD now, and all the x* sites have been squatted by porn.
They caught it 30 minutes before the demo - my friend almost choking on his coffee when he absentmindedly clicked one of the links - and they had to search and replace the whole database to be "example.com" everywhere.
Interestingly, xxxxx.xxx hasn't just been squatted by some porn provider. It appears to be owned and run by ICM Registry LLC, the registry for .xxx and the company which convinced ICANN to allow them to run the TLD.
So basically, the company that lobbied for and created .xxx didn't just know that people were going to squat xxxxx.xxx ___domain names used as placeholders, they actually got in on the act themselves before anyone else could.
